1. Field of the Invention
The present invention pertains to meat encasing machines for manufacturing sausages, wieners and the like (hereinafter simply referred to as sausages). More particularly, the present invention pertains to a sausage linker mechanism for use with a sausage stuffing machine. The linker mechanism of the present invention includes an improved casing lock for holding a sausage casing to a stuffing horn during a link twisting operation, wherein the stuffing horn is rotated.
2. Related Art
Sausage stuffing machines typically have an elongated stuffing horn, or nozzle, upon which is mounted a shirred flexible casing. A chuck is mounted on the machine and receives the discharge end of the stuffing horn through which meat emulsion is extruded. The end of the stuffing horn and the shirred casing thereon are inserted through the chuck, and the assembly is rotated by a suitable drive mechanism. A linking mechanism downstream from the discharge end of the stuffing horn serves to grasp the filled casing to hold it against rotation. Thus, the opposing forces exerted on the casing by the chuck and the linking mechanism cause the casing to twist at longitudinal increments defined by the distance between the discharge end of the chuck and the point where the filled casing is grasped by the linking mechanism. If no radial pressure is applied to the sausage casing at the end of the extruding nozzle, during the link twisting operation, then the casing will not rotate with the nozzle. This results in an improper twisting of the casing along the extruding horn instead of at the point between sausage links.
One related art device has a casing lock mechanism that includes a rubber diaphragm mounted within a rotating device and around a stuffing horn or nozzle. The rotating device is driven by a belt drive to synchronize its rotation with the rotation of the nozzle during a link twisting operation. However, this type of casing lock mechanism suffers several disadvantages. First, because of part tolerances, it is difficult to maintain an even pressure between the rubber diaphragm and the sausage casing during the link twisting operation. Second, when a link twisting operation is not being carried out, as for example during an extruding part of a sausage stuffing cycle, the rubber diaphragm exerts a radial pressure against the casing thereby producing unnecessary drag on the casing. But such radial pressure and drag are not necessary at times other than during a link twisting operation and, therefore, there is a risk that the sausage casing will be torn during an extruding operation.
U.S. Pat. No. 4,583,264 to Nausedas and U.S. Pat. No. 5,199,921 to Townsend are similar to the related art sausage stuffing machine discussed above in that they both include chucks that exert a radial pressure on the sausage casing at all times during the stuffing operation, i.e., during both extruding and link twisting operations. Therefore, these patents suffer the same disadvantages as the related art sausage stuffing machine in that they produce an unnecessary drag on the sausage casing, which drag may lead to a failure of the casing.
U.S. Pat. No. 3,964,128 to Townsend attempts to reduce casing failures by providing a fin head mounted to the end of a stuffing tube, by a spring, wherein the fin head is rotatable over a limited range relative to the stuffing tube. However, Townsend's fin head includes radially extending fins which, although bendable, exert a drag on the sausage casing at all times, i.e., during both the extruding and link twisting operations. Therefore, Townsend still suffers disadvantages similar to those mentioned above in that there is an increased risk of casing failure due to the unnecessary constant outward pressure on the casing.